After being acquired by breakfast and snack food conglomerate Kellogg for $600 million last year, Chicago-based protein bar maker RXBAR decided it was time for an office upgrade.
So earlier this year, the RXBAR team moved a few blocks over in River North to a new nine-story building at 412 N. Wells St. for a 10-year lease. How much RXBAR is leasing the building for is unknown, but a Spanish investor is paying more than $31 million for it, making it the most expensive office building per square…
